The latest in our series of briefings. Like all of the briefings this one is just two sides of A4 and is published under a Creative Commons license which means you are welcome to share, adapt and reuse the content. Download a PDF version here.
Check through the news bulletins and the financial papers and you’ll find hydrogen in the news. Big energy companies, the Westminster and Holyrood governments and some trade unions are all heralding hydrogen as a ‘green’ alternative to the natural gas which most of us use for heating and cooking. For example, SGN who run Scotland’s gas network are promoting a plan in which hydrogen would be produced and stored at the St Fergus gas terminal, north of Peterhead. It envisages starting to use hydrogen in Aberdeen and then extending the hydrogen network to the rest of the northeast coast and the central belt by 2045.
Natural gas used for heating and cooking accounts for around 30% of the UK’s carbon emissions. In contrast burning hydrogen for heat results in zero emissions. So, it appears that replacing natural gas with hydrogen is a no brainer. In this briefing we’ll explain why that’s not the case.
Grey, blue and green?
You will hear talk about grey, blue, and green hydrogen. The colours refer to how the hydrogen is produced – and it’s the production method that determines the impact of hydrogen on the environment.
Grey hydrogen is made from natural gas. Almost all the hydrogen that’s in use now is produced in this way. World-wide production currently amounts to 70 million tonnes. Greenhouse gases are a by-product of the production process, and current production has a similar impact on global warming to the whole aviation industry.
Much of the current hype is over blue hydrogen. Blue hydrogen is produced from natural gas in the same way as grey – the difference is that the production process incorporates carbon capture and storage. Greenhouse gases are stored rather than released to the atmosphere. Using blue hydrogen for all our domestic heating and cooking would require carbon capture on a massive scale. Large-scale carbon capture is untested, the technology for capture is not yet available and there are serious concerns about the long-term safety of large-scale storage. The production process for blue hydrogen is energy intensive and needs large amounts of green electricity. One example – Northern Gas Networks have a plan to convert domestic gas supplies to hydrogen. The aim is to have converted 15.7 million homes by 2050. This would require 8 million tonnes of hydrogen and need the equivalent of 60 production plants of the size of the largest currently operational plus a huge deployment of unproven carbon capture and storage technology.
Green hydrogen is produced by electrolysing water – if that electricity is from a renewable source the process is zero carbon. However, the process requires even more green electricity than producing blue hydrogen. The NGN scheme to supply 15.7 million homes would require around seven times as much wind generated electricity as is currently produced in the UK.
Generating electricity to provide the energy to ‘reform’ natural gas or electrolyse water into hydrogen and then using the hydrogen for heat is inherently inefficient. Direct use of electricity is cheaper, more efficient and would require much less generating capacity.
So why the hydrogen hype?
A new hydrogen economy (dependent on carbon capture and storage technology) is at the heart of the North Sea Transition Deal, dreamed up by the industry body Oil and Gas UK, published by the UK government in March 2021 and endorsed by Holyrood. The transition deal aims at continuing extraction of oil and gas through to 2050 and beyond. It is a costly diversion. To be sure of cutting emissions with the speed that is required we need to phase out oil and gas and invest in proven technologies that are based on renewable energy sources.
Ed Matthew Associate Director at independent climate and energy think tank E3G says hydrogen is the wrong choice for heating homes. Blue hydrogen (manufactured from natural gas) needs CCS so would be massively expensive and keeps us hooked on gas. Green hydrogen (made by electrolysis using renewable electricity) is 4 times less efficient than using heat pumps. “Hydrogen is being pushed by the gas industry. Beware.” Dave Toke, reader in energy politics at Aberdeen University agrees. He calls it: “the start of one of the greatest pieces of greenwash that have been committed in the UK.”
There is a place for hydrogen in a new sustainable economy. Hydrogen fuel cells supplied with green hydrogen are likely to be an integral part of a full decarbonised economy. Fuel cells work by using hydrogen to produce electricity which can then power a motor instead of using battery power, such as for electric vehicles.
Hydrogen fuel cells are currently better suited than batteries for long distance transport and to transport heavy loads. There are likely to be applications in energy storage and in some very specialised processes that are difficult to decarbonise. Sea transport may be a case in point
The main message of this briefing is that the hydrogen + CCS strategy is designed to maintain the profits of the big energy companies and will not achieve the cuts in carbon emissions that are needed. It puts profit before people and planet. There are alternatives that will work.
To decarbonise heat, we need retrofitted insulation, heat pumps and district heating schemes on a mass scale that can only be achieved by the public sector.
Firms producing filthy-dirty “grey” hydrogen must be required to take action to reduce the horrendous levels of greenhouse gas emissions they produce.
Hydrogen use must be limited to applications that are socially useful and don’t add to the climate crisis.
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